1. Field
The present disclosure generally relates to systems and methods of cooling electrical components and, in particular, allowing passive cooling while also providing ElectroMagnetic Interference (EMI) shielding.
2. Description of the Related Art
Hospitals have a need to provide secure storage for certain medications, such as narcotics and controlled substances, while still making the medications available to care givers. One method of providing this secure storage is the use of Automatic Dispensing Machines (ADMs), which typically contain a microprocessor that is functionally connected to the hospital data systems and secure drawers and compartments containing the medications. The software of each ADM is normally configured to allow access to the medications only after certain requirements are met, such as verification that the individual requesting the medication is authorized to do so. The ADMs should be continuously operational as hospitals must provide care to their patients 24 hours a day.
Computer processors and motherboards are known to emit electromagnetic radiation across a wide frequency band due to the high frequency digital signals conducted through the circuits of the processor and on the board. To meet regulatory requirements that limit the amount of electromagnetic energy that can be radiated from electronic devices, processors are frequently mounted inside conductive enclosures. However, placing the processor and motherboard inside a sealed conductive shell has the effect of limiting the amount of cooling air that can enter and leave the enclosure, and therefore a fan is often used to force air through the enclosure to cool the internal electronics, as the processor will overheat without sufficient cooling and shut itself down to avoid permanent damage. These fans are typically considered to be noisy. Also, since the functioning of the fan is critical to the operation of the processor and therefore the ADM, the fan is a potential source of downtime of the equipment.